Earth formations may be used for various purposes such as hydrocarbon production, geothermal production, and carbon dioxide sequestration. In order to efficiently employ resources for using an earth formation, it is necessary to know the permeability of the formation. Permeability relates to a value that characterizes the ability of the formation to transmit fluids through the formation. For hydrocarbon production purposes, the fluids are generally transmitted from a reservoir in the formation to a borehole penetrating the formation.
Reservoir engineers use the permeability of a formation to plan for well locations and their depths as well as extraction flow rates among other engineering decisions. In general, fluids flow through fractured rock in the formation. Because these fractures can have various orientations, the value of permeability is generally a function of direction. Hence, by knowing the directional permeability of a formation or of different portions of the formation, the reservoir engineer can more accurately plan wells and thus make a more efficient use of expensive production resources.